A 1.200kg block of phosphorus-32, which has a half life of 14.3 days, is stored for 100.1 days. At the end of this period, how much phosphorus-32 remains/ and show did u solve it

Two steel balls, each of mass m, are welded to a light rod of length l and negligible mass and are initially at rest on a smooth horizontal surface. a horizontal force of magnitude f is suddenly applied to the rod as shown. determine (a) the instantaneous acceleration a of the mass center g and (b) the corresponding rate at which the angular velocity of the assembly about g is changing with time.